The present invention relates to a golf ball having oval dimples.
It is well known that in designing golf balls, in order to design a golf ball that travels a long flight distance when it is hit, it is important that the golf ball itself have a high resilience and that the air resistance applied during travel be reduced by dimples arranged on the surface of the golf ball.
For example, Japanese Patent Application Publication No. 08-191905 discloses a method intended to increase the flight distance by generating a large amount of turbulence in the air around the golf ball and decrease the difference in the flight distances between the distance travelled in the case of a hit at the pole and that travelled in the case of a hit at the seam, in which the golf ball includes dimples having a circular planar shape and non-circular elliptical dimples, the total number of the elliptical dimples is 20% or more of the total number of the dimples, and the dimples are arranged so that the average crossing acute angle δ between a line passing through the center of each elliptical dimple and the pole and the major axis of each such dimple satisfies 0≦δ≦80°.
In addition, Japanese Patent Application Publication No. 2012-130603 discloses a method intended to provide a golf ball capable of travelling a great flight distance when hit with a driver at a head speed of 45 to 55 m/s, in which a plurality of types of dimples of mutually different diameters is provided on the surface of the golf ball, the standard deviation of the radiuses of curvature on the cross section of all the dimples is 0.90 mm or less, the mean value of the radiuses of curvature on the cross section of all the dimples is 20 to 40% of the diameter of the golf ball, the total value of the volume of all the dimples is 300 to 370 mm3, the mean value of the diameters of all the dimples is 3.5 to 4.5 mm, and the ratio of the total value of the areas of all the dimples in relation to the surface area of the virtual sphere of the golf ball is 75 to 95%.